The Bulk Water Alliance's Enlarged Cotter Dam Project has been recognised as the best civil infrastructure project at the Master Builders Australia National Excellence in Building and Construction Awards.

The project was among 5000 entries in the regional, state and territory awards competing for 41 honours.

It was recognised as one of the best examples of construction in Australia in the past year and was commended on its environmental management.

The Cotter Dam expansion has increased Canberra's water storage capacity by 35 percent and holds 76 gigalitres of water.

More than 3000 workers expanded the dam over three years.